Conventional side gas bag modules comprise an elongated housing that has first and second side pieces which are connected by means of a spine portion and have edges as well as inner faces lying opposite each other, a gas bag arranged folded in the housing and at least one flap provided on the edge of the first side piece remote from the spine portion, which flap is pivotally connected via a hinge with the first side piece.
Such side gas bag modules are used to accommodate side gas bags which have a large area, which extend for example from the A- to the C-column of a vehicle. The side pieces of the housing define here a so-called ejection channel, through which the gas bag emerges on activation of the module during unfolding.
The opening of the ejection channel, which is defined by the edges of the side pieces a distance remote from the spine portion, is closed hitherto for example by latching connectors arranged at intervals. These latching connectors are forced open by the unfolding gas bag on activation of the gas bag module and then free the opening of the ejection channel.
Modern side gas bags have several inflatable chambers which are separated from each other by non-inflatable areas, in order to be able to keep the quantity of required inflation gas low and to optimize the restraint characteristics of the gas bag. The non-inflatable areas of the gas bag generally run over far distances parallel to the unfolding direction of the gas bag. For the unfolding of the gas bag from the housing, this means that during the initial phase of unfolding, in which the gas bag is still arranged in the housing, the non-inflatable regions can exert no or only a little force onto the latching connectors which close the housing. Therefore, in these regions, a greater spacing of the latching connectors is selected for closing the opening of the ejection channel. A similar situation applies with the presence of an A-column chamber, which only has a small volume. When being filled with gas, such a chamber can likewise only exert a small force onto the housing. Conventional gas bag module housings remain in this region either unclosed or are only closed by a few latching connectors. Between the latching connectors, the housing is often only closed by an overlapping of the walls of the side pieces. Through costly measures, it must be ensured that the gas bag does not work itself out from the housing at these points in the course of time, owing to vibrations of the vehicle.
From EP 1 055 566 A2 there is known a generic side gas bag restraint system, in which the first side wall is approximately twice as wide as the second side wall. An over-wide flap is formed on the first side wall, which supplements the second side wall and is fastened to it by means of a latching nose having a small width. The second side wall is of such a small width that the folded gas bag almost does not adjoin it at all. Rather, the first side wall is formed with its flap into a “U”, in which the folded gas bag is housed. However, in case the gas bag applies a pressure onto the flap, then the danger exists that the latching nose slides along the free edge of the second side piece, a distance remote from the spine portion of the housing, and the housing opens at least in parts. A further disadvantage of the known housing consists in that the unfolding direction is not predetermined by the housing itself, i.e. no ejection channel is provided, i.e. a channel between the two side walls in which the gas bag is moved on unfolding.
It is an object of the invention to present a side gas bag module in which the ejection channel opening can be closed completely and securely in a simple and favorably-priced manner.